On Charles Darwin's 207th birthday, a new study of evolution in a diverse group of wild tomatoes is shedding light on the importance of genetic variation in plants.

by Jim Erickson, U-M News Service and Kevin Fryling, Indiana University

On Charles Darwin's 207th birthday, a new study of evolution in a diverse group of wild tomatoes is shedding light on the importance of genetic variation in plants.

The work, reported Feb. 12, 2016 in the journal PLoS Biology, uses genome-wide sequencing to reveal details about the evolutionary mechanisms that drove genetic divergence in 13 species of wild tomatoes that share a recent common ancestor.

First author of the study is University of Michigan postdoctoral fellow James Pease, who conducted the work for his doctoral dissertation at Indiana University. The in-depth genetic analysis was led by IU's Leonie Moyle.

"This study reveals new details about the unexpectedly complex genetic mechanisms that drive the diversification of plant species," said Moyle, who conducted the research as the primary investigator on a $1.18 million grant from the National Science Foundation.

"The vast biodiversity we observed in tomato species was not the result of simply one evolutionary or environmental factor. It is the result of a complex set of genetic resources that we can distinguish with large-scale genomic data," said Pease, who joined the U-M Department of Ecology and Evolutionary Biology in June 2015.

The research may contribute to future efforts to create more resilient crop plants in a time of changing climate by boosting resistance to pests or severe weather using crossbreeding methods rather than genetic engineering.

Tomatoes were used for the study because they are an ecologically and reproductively diverse plant group, said Moyle, who was part of a team of researchers that visited Ecuador in May 2014 to collect different populations of tomatoes native to the Andes Mountains, a biodiversity hotspot.

Although better known for his work on finches, Darwin also hunted on the Galapagos Islands of Ecuador for wild tomatoes, one of the hundreds of plant and animal species collected by the British naturalist during his landmark trip to the archipelago in 1835.